(1) An investigation was made to measure the change in diffusion current after prolonged reduction about one or two hours, and to relate it to the total current which had passed in order to find the number of electrons involved per molecule in the reduction of Sodium m-nitrobe-nzene sulfonate.The volume of electrolytic solution used was about 0.3cc.
(2) An assumption had been made by Cilbert that under such conditions electrolytic solution was completely mixed up by dropping mercury. But the writer was confirmed that contrary to this assumption it was necessary to stir the solution in some proper way at intervals during the reduction process.
(3) It was made clear that ager saturated with potassium chloride was most proper for the salt bridge from an external anode to the solution.